Optimal Emissions Taxation under Imperfect Competition in a Durable Good Industry

This paper investigates optimal emissions taxation under imperfect competition in a durable good industry where products are sold (instead of rented). As a benchmark, attention is paid to the special case of monopoly with exogenously given product durability. In line with previous literature, the optimal emission tax in this benchmark model falls short of marginal damage (underinternalization). Extending the benchmark model either to the case of an oligopolistic market structure and/or to the case of endogenous product durability then provides two cases in which the optimal emission tax overinternalizes marginal damage.     

精馏过程的节能和优化设计的探讨

精馏过程的节能,对于减少能源消耗,降低生产成本和保护环境具有十分重要的意义.在精馏过程中可以采用最适宜回流比操作和最佳进料状态,使用中间冷凝器和中间再沸器,高效精馏、热泵精馏.合理安排多组分物料分离流程,直接利用过程热量及开发应用高效换热器等措施.本文从最佳回流比R的选择、进料温度及进料状态的确定等方面,详细的分析了在精馏塔的设计过程中,如何实现设计的优化问题,以实现节能降耗.     

Designing Optimal Crop Revenue Insurance

When the indemnity schedule is contingent on the farmer's price and individual yield, an optimal crop revenue insurance contract depends only on the farmer's gross revenue. However, this design is not efficient if, as is the case with available contracts, the coverage function is based on imperfect estimators of individual yield and/or price. The producer's degree of prudence and the extent of basis risks have important influences on the optimal indemnity schedule. In this broader context, optimal protection is not provided by available U.S. crop insurance contracts and may include combinations of revenue insurance, yield insurance, futures, and options contracts.     

对小地区失业统计差额比的推定

本文对韩国国内行政区域如市郡区等小地区的失业统计共同差额比进行推定的方法有联合推定量,Woolf推定量和Mantel-Haenszel推定量等。对这个推定量的可信度是通过偏差和平均平方误差的概念来进行比较的。从对京畿地区经济活动人口调查情况看,这个地区内的24个市郡单位行政自治地区的男、女失业率差额比的偏差及平均平方误差是通过本次研究提出的推定程序来推定的。这些推定数的稳定性和效率性可以通过相对偏差和相对平均误差平方根来评价。Woolf推定量或Mantel-Haenszel推定量比联合推定量更为稳定,从其效率性来看三者很相似。     

Tinbergen in De Economist

Jan Tinbergen's scientific writings cover six main areas of research. His articles in De Economist represent these areas; in some cases the contributions to De Economist were of a pioneering nature (business cycles, economic models, economic integration); in others De Economist was the first or even single outlet for Tinbergen's work. This article provides an overview of these contributions. The wide scope of Tinbergen's areas of research goes together with a unity in approach, the characteristics of which are: policy relevance, quantification and measurement, balance in analysis and presentation, and learning from experience. Tinbergen's articles in De Economist bear witness to this approach which at the time also met with scepticism and resistance as this overview shows. According to Houthakker, Tinbergen's main contribution may be that, amidst the pleas of interest groups and the slogans of the laity, an attempt is made that the voice of the professional economic researcher be heard. Tinbergen's work still sets an agenda for both economic research and policy making.     

Discussion and Analysis about Duration Method Based on Marginal Analysis

The selective principle of mutually exclusive project is the maximum of net present value, It is difficult to make decision when NPVA is equal to NPVLB. Some assistant analyses are put forward in ＂Enterprise Investment Decision Management＂. The scientific marginal analysis shows that the assistant analyses including the duration analysis are wrong. This problem can be solved by the classical marginal analysis.     

中国税收流失规模估测

无论地下经济还是公开经济都存在税收流失问题.本文采用一定的方法分别对我国1982-2002年间地下经济和公开经济的税收流失规模进行了估测.从税收流失的规模角度看,我国税收的汲取能力比较弱,蕴涵着很大的税收风险.减少税收流失应作为税制改革的重要目标.     

FACTORS THAT AFFECT THE LONG‐TERM SURVIVAL OF MICRO,SMALL AND MEDIUM ENTERPRISES IN ETHIOPIA

There is an increasing recognition of the potential importance of micro, small and medium enterprises (MSMEs) for employment, income and poverty reduction in Ethiopia. Although the MSME sector contributes significantly to the national economy, the high failure rate among well established small businesses and enterprises is a matter of major concern. A random sample of 500 small businesses and enterprises selected from five major cities in Ethiopia were followed up for 6 years in order to assess the impact of influential factors that affect the long‐term survival and viability of small enterprises. Hazard ratios estimated from the Cox Proportional Hazards Model were used to quantify the impact of key predictors of survival. Businesses that ceased operation were characterised by inadequate finance (61%), low level of education (55%), poor managerial skills (54%), shortage of technical skills (49%), and inability to convert part of their profit to investment (46%). The study shows that participation in social capital and networking (iqqub schemes) was critically helpful for long‐term survival. Businesses that did not participate in iqqub schemes regularly were found to be 3.25 times more likely to fail in comparison with businesses that did. Results of the study have implications that could be used for developing policy initiatives that are aimed at fostering long‐term growth in small businesses and enterprises.     

积分循环赛在学校篮球竞赛中的应用研究

为了在学校篮球竞赛中引入积分循环赛，文章针对棋类积分编排存在的三个方面问题，通过采用每轮比赛排名作为配对排序的条件，并对棋类积分编排方法进行了一定的简化移植，经过多次试验性编排，运用电子表格技术设计出了一整套篮球积分编排方法。这种方法可实际运用于篮球积分循环赛的手工编排，并能为实现计算机篮球积分编排提供理论依据。     

Generalized piecewise linear histograms

We extend the concept of piecewise linear histogram introduced recently by Beirlant, Berlinet and Györfi. The disadvantage of that histogram is that in many models it takes on negative values with probability close to 1. We show that for a wide set of models, the extended class of estimates contains a bona fide density with probability tending to 1 as the sample size n increases to infinity. The mean integrated absolute error in the extended class of estimators decreases with the same rate n^–2/5 as in the original narrower class.